Microwave oven



FIG. 1 is a right side elevation view of a microwave oven showing our new design;

FIG. 2 is a left side elevation view thereof;

FIG. 3 is a top plan view thereof;

FIG. 4 is a rear elevation view thereof;

FIG. 5 is a bottom plan view thereof; and,

FIG. 6 is a front left perspective view thereof, with the lid in an open position.

The broken lines shown in FIGS. 2, 4, 5, and 6 illustrate environmental subject matter and form no part of the claimed design. 

CLAIM The ornamental design for a microwave oven, as shown and described. 